The present invention relates generally to oiling systems for internal combustion engines, and more specifically, to a temperature control to vary oil delivery to a two-cycle/two-stroke engine of an outboard motor.
Typically, two-stroke outboard marine engines do not have a separate oiling system. That is, these prior art engines require pre-mixing lubricant and fuel so that the lubricant dissolves in the fuel to lubricate the engine. This requires consistent, accurate measuring and agitation of the mixture. There are many disadvantages to the prior art system of pre-mixing lubricant and fuel. For example, since various two-stroke engines require different mix concentrations, many outboard marine engine owners also own other two-stroke engine equipment, such as various lawn and garden equipment and ATV""s, they may store several different concentrations of oil/fuel mixture. This is not only an aggravation to the owner, but is also problematic if the containers become mixed up and the owner uses the wrong concentration for a particular two-stroke engine. While this is not catastrophic, if run over time with the wrong concentration, a two-stroke engine can wear excessively.
The present invention is for use in a unique lubrication system for two-stroke engines. Such a lubrication system must not only provide lubrication to each cylinder of the engine, it must also provide lubrication to the fuel system to properly lubricate the fuel metering and injection system.
Two-stroke engines are used in a variety of applications under many different temperature conditions. Current oiling systems for two-stroke engines do not provide temperature compensation for the delivery, of oil as the temperature of the oil changes. Since the viscosity of oil increases with decreasing temperature, without any compensation, oil delivery to the engine can decrease resulting in insufficient oil delivery and the potential of serious engine damage. Conversely, as temperature of oil increases, the viscosity of the oil decreases. Without proper compensation, such a decrease in the viscosity of the oil can result in an increased amount of oil delivered to the engine resulting in excess oil consumption and engine smoking.
It would therefore be advantageous to provide temperature compensation control in an oiling system for a two-stroke engine to modify oil delivery based on the viscosity of the oil.
The present invention discloses an oil temperature compensation control for use in an oil delivery system for a two-stroke engine that solves the aforementioned problems.
In accordance with one aspect of the invention, a temperature compensation control for an oiling system includes an oil injection system that periodically routes lubricant to an engine and a temperature sensor to acquire an oil temperature indicative signal. A microprocessor is connected to receive the oil temperature indicative signal from the temperature sensor, and in response thereto, controls the time period lubricant is routed to the engine by the oil injection system in order to compensate for the viscosity of the oil for various temperatures.
In accordance with another aspect of the invention, an outboard motor having an internal combustion engine and an oiling system to distribute oil to the internal combustion engine is disclosed. The oiling system has a closed loop re-circulation system that includes a remotely located oil reservoir. The oiling system also includes an oil flow control section that periodically diverts lubricant to the internal combustion engine. A temperature sensor is provided to acquire a temperature signal having a relationship to the viscosity of the lubricant in the remotely located oil reservoir. The outboard motor includes a control to receive and process the temperature signal from the temperature sensor, and then to adjust the period that lubricant is diverted to the internal combustion engine in response to the temperature signal to compensate for viscosity changes in the lubricant.
The invention also includes a method of providing lubricant to a two-stroke engine that includes acquiring a temperature signal that is indicative of the temperature of a lubricant supply and correlating the temperature signal to a viscosity of the lubricant. The method next includes adjusting lubricant flow to the two-stroke engine based on the viscosity of the lubricant.
The invention includes a computer program that causes a computer to periodically acquire a temperature signal that is indicative of the lubricant temperature and then adjusts lubricant flow to an engine in an outboard motor based on the lubricant""s viscosity. The temperature signal acquired can be that of ambient temperature of the outboard motor that is then correlated to oil viscosity and converted to a pulse width signal to control a solenoid that in turn controls lubricant flow to the outboard motor.
Various other features, objects and advantages of the present invention will be made apparent from the following detailed description and the drawings.